Interface Testing

What is ​Interface Testing?

Before understanding Interface Testing, we must have knowledge of what is interface in the computer world? For developing any software we need different components, these components can be of the same or different software. These can be database servers in single software or if we talk about an e-commerce application, Payment Gateway is a different software integrated with an e-commerce website/ application. So Interface is the connection between two or more components integrated into a single unit. The connection between the components is done by APIs, Web Services, etc.

So it is done to verify and test the communication between the two software or the components of the same software. It involves testing of interfaces like APIs and web services. Interface testing is one of the most important testing in order to ensure smooth and safe communication between the components in software. An interface is basically a software that involves a set of commands, images, messages, etc to enable the communication between the user and a device. There are many security reasons that need to be tested when the data is transferred from one software to another and these security tests are performed in Interface testing. Interface testing is performed only on the code and is almost automated.

Why do we need Interface Testing?

Prior to performing anything, it is very important to understand its importance. Consider a scenario of e-commerce websites like Flipkart, Amazon, etc. It has a web application, database and server to run the whole application. This transfer of data from a web application to the database is not done directly due to some security concerns and is basically done with the help of APIs and web services. If the user login or signup in the application through UI, the data is sent to the database. There are certain scenarios like unauthorized user tries to store or access the data, some server error while retrieving or manipulating data, etc. In order to ensure that such problems should not happen and the smooth flow of all the integrated components should work, interface testing is performed.

There are some key points which depict the need for Interface testing:

• In order to ensure the smooth functioning of application for the end-user.
• In order to check the security breach in an application while communication between the two or more interfaces.
• To verify that the communication is capable enough to handle various situations like network failure, server restart, etc.
• To verify error handling is done properly and the correct error message is displayed to the user for various situations.

How Interface Testing is Performed?

There are 2 components involved in Interface testing:

1. Web server and application server interface
2. Web server and database server interface

Almost all the test cases of Interface testing are automated.

Basically, 3 phases are involved in the Interface testing which is mentioned below:

1. Configuration and Development​

When the interface between the software components is configured and the development of the application starts, then the verification is done as per the documents.

2. Validation

​After the development, validation and verification of Interfaces are done.

3. Maintenance

​This is done after the whole software is developed, interfaces are created, deployed and hand over to the client. It is maintained by a team of testers checking for if any new issues are introduced and security breaches found in the interfaces.

Interface testing basically involves testing of ReApi and Soap web services of an application having the data in the form of JSON and XML format and is done at the messaging layer. It involves testing like Unit testing, Load testing, Security testing, Workflow testing, error detection, etc. Like other testing processes, Interface testing also requires proper planning and strategic approach and involves the step by step procedure for its execution like Requirement gathering, defining the expected output, defining the start and stop endpoints, etc.

Advantages and Disadvantages of Interface Testing

Following are the advantages and disadvantages of interface testing are as follows:

Advantages

1. It helps to verify the communication between two or more components in an application which is one of the most important tasks for the proper functioning of application.
2. It helps to check the security policies of application for communication between components in an application.
3. It helps to understand the application behavior in case of network or server issues.
4. It helps to find out the areas of application which are commonly used by the users so that they can be properly tested.

Disadvantages

1. Testing is done only on the code, so a specialized team of testers is required for this which demands high cost and increases the overall budget of the project.
2. A lot of time is wasted in creating and running the automated scripts which are sometimes not very helpful in case of small projects.
3. People with a high skill set is required to perform Interface testing.
4. Interface testing is sometimes very boring and tricky too.

Tools used for Interface Testing

As mentioned above, test cases of Interface testing are almost automated. So the Automation testing tools which are basically used for Interface testing are given below:

Postman

Postman is commonly used in the market for the Rest API Test cases that can be executed in Postman either manually or through automation. It is Chrome’s extension and is also available for MAC, Linux Operating Systems. 

SoapUI

SoapUI is one of the most popular tools used for API and web services testing in the market. It accepts the data in the form of CSV and excel format and produces the desired output.

Jmeter

 ​Though the JMeter is mostly used for Performance testing, it can also be used for Interface testing as it provides features like record and play. It is easy to integrate it with Jenkins also so very helpful for CI/ CD applications.

Conclusion

Like another testing, Interface testing plays an important role in testing the software and ensures that the end-user should not face any problem while using the software. As the interface testing is quite tricky, proper planning needs to be done before performing it. So the best way to perform it is to automate the test cases which help in achieving better results.

Recommended Articles

This is a guide to Interface Testing. Here we discuss what is interface testing, why there is a need for this testing, how it is performed and interface testing tools along with the advantages and disadvantages and tools used for interface testing. You may also look at the following articles to learn more –

• GUI Testing
• Security Testing
• Penetration Testing
• Static Testing